<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        body {
            background-color: #000;
            margin: 0;
            overflow: hidden;
        }
        @keyframes sky {
            from {
                opacity: 0.4;
            }
            25% {
                opacity: 1;
            }
            50% {
                opacity: 0.4;
            }
            75% {
                opacity: 0.1;
            }
            to {
                opacity: 0.4;
            }
        }
        .sky {
            background-image: linear-gradient(#03f, #fff);
            height: 700px;
            animation: sky 15s ease-in-out infinite;
        }
        @keyframes sun {
            from {
                top: 650px;
                left: 100px;
                opacity: 0.4;
                transform: scale(0.7, 0.7);
            }
            25% {
                top: 100px;
                left: 700px;
                opacity: 1;
                transform: scale(1, 1);
            }
            50% {
                top: 650px;
                left: 1300px;
                opacity: 0.4;
                transform: scale(0.7, 0.7);
            }
            75% {
                top: 800px;
                opacity: 0.1;
            }
            to {
                left: 100px;
                opacity: 0.4;
                transform: scale(0.7, 0.7);
            }
        }
        .sun {
            position: absolute;
            width: 120px;
            height: 120px;
            border-radius: 50%;
            box-shadow: inset 0 0 15px #fc0,
                inset 0 0 30px 30px #fb0,
                inset 0 0 50px 45px #fa0,
                0 0 15px #fd0,
                0 0 30px 20px #fe0,
                0 0 50px 50px #ff0;
            top: 650px;
            left: 100px;
            animation: sun 15s ease-in-out infinite;
        }
        @keyframes moon {
            from {
                top: 650px;
                left: 1300px;
                opacity: 0.4;
            }
            25% {
                top: 800px;
                opacity: 0.1;
            }
            50% {
                top: 650px;
                left: 100px;
                opacity: 0.4;
            }
            75% {
                top: 100px;
                left: 700px;
                opacity: 1;
            }
            to {
                top: 650px;
                left: 1300px;
                opacity: 0.4;
            }
        }
        .moon {
            position: absolute;
            top: 650px;
            left: 1300px;
            width: 128px;
            height: 128px;
            background-image: url(./月亮.png);
            transform: rotate(-25deg);
            animation: moon 15s ease-in-out infinite;
        }
    </style>
</head>
<body>
    <div class="sky"></div>
    <div class="sun"></div>
    <div class="moon"></div>
</body>
</html>